If a friend on Facebook tells you they met a celebrity what are the odds of them the truth?

[J5000]

For example, a friend of mine on Facebook was in California, she posted photos of her there. I wrote her and asked her if she saw any celebrities. She said she not only saw one but she bumped into him on a plane. Is she likely lying or could she be telling the truth? Celebrities don't even ride public airplanes do they?
I think she is lying but if I told her that she would get mad and she might not be my friend anymore

[714]

It's quite easy to run into them from time to time, I have walked past a few major celebrities, spoke to some too. I see no reason to lie about it, they do live in the same world.

[SOCIAL-WACKO]

Some definitely do ride public planes, the question is if she did run into a celeb wheres the autograph/picture? Shes probably making it up without proof I would say she probably saw the celeb in her dreams and is definitely making it up, Hell I could say I went cliff hanging with Sylvester Stallone. Believe me? probably not.

[Abigail]

There's no better proof than a picture